It is used to develop server side stuff, so it includes a lot of libraries used on server side.

JavaME: is the mobile edition, it is what small games on old phones was made with, but it's basically a 'smaller' version of Java suitable for very low capacity processors.

JavaSE: is the standard edition, it is usually a good fit for client side software, normal applications, etc.

Basically, since the Java ecosystem is huge, Sun decided to offer Java in different editions: When talking about JavaSE, JavaEE, JavaME etc. If you want to seriously develop Java applications, you need the JDK. It also usually contains documentation for the standard library and also all the sources of the standard library, because they are useful for developers to read and inspect. jar files, many tools for 'decompiling' class files, inspect. That includes the compiler obviously (which is also contained in the JRE for some good reason, but you can ignore this fact now), the JAR utility to create. It contains the JRE as well as a lot of other useful stuff for developing Java applications. If you are running any Java program on your computer, you have a JRE installed. all the way to 1.7, also known as Java 7) usually contain improvements to both the JVM and the standard library, so the two usually need to run together, and are packaged together in the JRE.

It contains all the stuff in java.* packages and some private stuff in com.sun, com.oracle packages.ĭifferent versions of Java (1.0, 1.1, etc. The standard library is itself very important, because it contains a lot of useful things you'll use when developing Java applications. It includes everything needed to run a Java application, that is the JVM itself, the standard library and a bunch of other files. However, commonly a sysadmin will say 'the JVM' to indicate the actual binary running on the server). (many will disagree and say that the JVM is only one, and it's a specification. but there are also many alternative JVMs, JVMs for embedded device etc. There are many JVMs, for example you need a JVM for Windows, one for Linux, one for OSX etc. class files packaged together) and execute it. It is a program that can read compiled Java code (the. You didn't ask for it, but I'll start from here.

Java se kit 8